\begin{tikzpicture}
    \tkzDefPoints{0/0/B', 4/0/C', 3.5/3/A', 0/1.5/B,  4/1.5/C}
    \tkzDefLine[parallel=through B, normed](B',A') \tkzGetPoint{a}
    \tkzDefPointOnLine[pos=3](B,a)  \tkzGetPoint{A}
    \tkzInterLL(A',B')(B,C)    \tkzGetPoint{D}

    \tkzDrawSegments(B',A' B',C'  B,A  B,C)
    \tkzLabelPoints[right](A',A)
    \tkzLabelPoints[below](B',C',B,C,D)
\end{tikzpicture}

